Conventional self-storing storm windows are generally of two types. In the first type, some of the sashes are attached to the supporting frame, and a sliding sash is guided by removable guides. This requires the use of tools if the sashes are to be removed.
The other type has multiple sashes riding in multiple fixed tracks. In order to facilitate removal of the sashes for cleaning, opposed sets of tracks have one track deeper than the other. A sash can be shifted into the deeper track until its opposite edge clears the other track, and can then be removed. With sashes removable in this way, there is no security against unauthorized entry through the window, since the sashes can be removed from either side. This type of structure is disclosed in U.S. Pat. Nos. 2,910,740 and 3,636,661. In addition, when one track is deeper than the other to allow installation or removal of sashes, there is an air space between the base of the deeper track and the adjacent edge of the sash. This is undesirable in a window, since it allows infiltration of air and water.
To facilitate removal of all sashes and still prevent unauthorized entry from outside, another design utilizes retractable pins mounted on the sides of the sashes. The pins, not the sash itself, ride in the tracks. With the pins retracted from the inside, the sashes can be be removed. This design, however, allows a considerable amount of air and water infiltration between the sashes and the tracks.